get off (one's) bike
To become angry or irritated. Primarily heard in Australia, Ireland. Don't get off your bike—I wasn't trying to insult you.
get off your bike
 AUSTRALIAN, INFORMALIf someone gets off their bike, they become so angry or upset that they cannot control themselves. It was just an accident — there's no need to get off your bike!
get off your bike
 become annoyed.Australian & New Zealand informal  1939 Xavier Herbert Capricornia ‘I tell you I saw no-one.’ ‘Don't get off your bike, son.—I know you're tellin' lies.’